The red car (deceased couple) was primarily at fault, as the driver was clearly trying to pass both the blue Lambo and the camper at the same time, and the red car initiated the collision from the rear.
Now, that said, about 70% of the drivers in this “rally” were driving like they were on speed. For example, note the car that nearly takes out the dude on the motorcycle...
To his / her credit, the driver of the car with the dashcam did a good job to maintain a safe distance, and is likely really glad he/she did!
Correction, the red Ferrari tried to pass at least THREE vehicles in one pass — he never drops back into the right lane.